[Posterior petrous meningioma with secondary trigeminal neuralgia: microsurgical resection after stereotactic radiosurgery (case report and literature review)]. / Meningioma zadnei poverkhnosti piramidy visochnoi kosti s vtorichnoi trigeminal'noi nevralgiei: mikrokhirurgicheskaya rezektsiya posle stereotaksicheskoi radiokhirurgii (klinicheskii sluchai i obzor literatury).

According to the literature, cerebellopontine angle tumors cause secondary trigeminal neuralgia and other symptoms of neurovascular compression in 1-9.9% of cases. We present a 58-year-old patient with left-sided secondary trigeminal neuralgia caused by ipsilateral posterior petrous meningioma. Stereotactic irradiation was followed by effective tumor growth control. However, residual trigeminal pain paroxysms significantly reduced the quality of life and required subsequent microsurgery. Trigeminal facial pain regressed after total resection of tumor. Considering this clinical case, we would like to discuss several issues: follow-up of meningioma requiring radiosurgery, course of secondary trigeminal neuralgia in a patient with apical petrous meningioma, characteristics of pain before and after radiosurgery, the best treatment option for these patients. Stereotactic radiosurgery seems unreasonable for CPA tumors with secondary trigeminal neuralgia. Indeed, persistent pain is possible even after tumor shrinkage. Moreover, primary stereotactic irradiation significantly complicates subsequent resection of tumor.

[Dysphagia as the main symptom in anterior cervical spine osteophytes (Forestier disease and cervical spondylosis deformans). Case reports and literature review]. / Disfagiya kak osnovnoi simptom pri perednikh osteofitakh sheinogo otdela pozvonochnika (bolezn' Forest'e i tservikal'nyi deformiruyushchii spondilez): obzor literatury i analiz klinicheskikh sluchaev.

Anterior cervical osteophytes are a fairly common X-ray finding in people over 50 years old. Incidence of dysphagia in patients with anterior osteophytes varies from 1% in those aged 40-60 years to 10.6% in patients over 60 years old. The most common causes of anterior cervical hyperosteophytosis causing dysphagia are cervical spondylosis deformans and Forestier disease. We present 2 clinical cases of spondylogenic dysphagia in cervical spondylosis deformans and Forestier disease. The review is devoted to the causes and diagnostic methods for dysphagia caused by anterior cervical osteophytes, as well as surgical options for this pathology. CONCLUSION: Microsurgical resection of anterior osteophytes is an effective method for dysphagia after ineffective therapy for 3 months. Microsurgical osteophytectomy provides stable regression of dysphagia with low recurrence rate.

The State Scientific Automated Medical Registry, Kazakhstan: an important resource for low-dose radiation health research.

Direct quantitative assessment of health risks following exposure to ionizing radiation is based on findings from epidemiological studies. Populations affected by nuclear bomb testing are among those that allow such assessment. The population living around the former Soviet Union's Semipalatinsk nuclear test site is one of the largest human cohorts exposed to radiation from nuclear weapons tests. Following research that started in the 1960s, a registry that contains information on more than 300,000 individuals residing in the areas neighboring to the test site was established. Four nuclear weapons tests, conducted from 1949 to 1956, resulted in non-negligible radiation exposures to the public, corresponding up to approximately 300 mGy external dose. The registry contains relevant information about those who lived at the time of the testing as well as about their offspring, including biological material. An international group of scientists worked together within the research project SEMI-NUC funded by the European Union, and concluded that the registry provides a novel, mostly unexplored, and valuable resource for the assessment of the population risks associated with environmental radiation exposure. Suggestions for future studies and pathways on how to use the best dose assessment strategies have also been described in the project. Moreover, the registry could be used for research on other relevant public health topics.

The electrostatic role of the Zn-Cys2His2 complex in binding of operator DNA with transcription factors: mouse EGR-1 from the Cys2His2 family.

The mouse factor Zif268, known also as early growth response protein EGR-1, is a classical representative for the Cys2His2 transcription factor family. It is required for binding the RNA polymerase with operator dsDNA to initialize the transcription process. We have shown that only in this family of total six Zn-finger protein families the Zn complex plays a significant role in the protein-DNA binding. Electrostatic feature of this complex in the binding of factor Zif268 from Mus musculus with operator DNA has been considered. The factor consists of three similar Zn-finger units which bind with triplets of coding DNA. Essential contacts of the factor with the DNA phosphates are formed by three conservative His residues, one in each finger. We describe here the results of calculations of the electrostatic potentials for the Zn-Cys2His2 complex, Zn-finger unit 1, and the whole transcription factor. The potential of Zif268 has a positive area on the factor surface, and it corresponds exactly to the binding sites of each of Zn-finger units. The main part of these areas is determined by conservative His residues, which form contacts with the DNA phosphate groups. Our result shows that the electrostatic positive potential of this histidine residue is enhanced due to the Zn complex. The other contacts of the Zn-finger with DNA are related to nucleotide bases, and they are responsible for the sequence-specific binding with DNA. This result may be extended to all other members of the Cys2His2 transcription factor family.

[RESEARCH OF INTESTINAL MICROFLORA IN THE RATS FOLLOWING THE INTERNAL AND EXTERNAL IRRADIATION].

The aim of the research was comparative investigation of the quantitative and qualitative composition of large intestinal microflora following internal (by dispersed powdered 56Mn) and internal exposure of Wistar rats. Ten weeks-old male Wistar rats were used. Rats were divided into four groups: L-56Mn group with 12 rats, H-56Mn with ten rats, 60Co group with nine rats and control group with nine rats. L-56Mn and H-56Mn groups were exposed to two different doses of 56MnO2 powder. 60Co group received 2 Gy of external 60Co γ-ray whole body irradiation. Totally 40 rats. Three rats from each group were sacrificed throw 6 hours and on days 3, 14, and 60 after the exposure. Animals were examined throw 6 hours and on days 3, 14 and 60 after exposure. Although the absorbed doses in large intestine were only 0.69 and 1.90 Gy in 56Mn exposed groups, respectively, changes in large intestinal microflora were evident. After 6 hours and on day 3 after 56Mn exposure amount of main representatives of large intestinal microflora (Bifidobacterium and lactobacilli) was decreased in the dose dependent manner. On the other hand, the amount of conditionally pathogenic bacteria was increased. These changes were persistent even on day 14. External 60Co γ-irradiation at a dose of 2 Gy also changed the intestinal microflora, but these changes were not persistent and on day 14 after irradiation returned to the control level. Our data suggest that internal exposure to dispersed powdered 56Mn has a significant biological impact on the intestinal microflora for a prolonged period of time, when it is compared with the effects of external radiation.

Calculation of dose conversion factors for doses in the fingernails to organ doses at external gamma irradiation in air.

Absorbed doses to fingernails and organs were calculated for a set of homogenous external gamma-ray irradiation geometries in air. The doses were obtained by stochastic modeling of the ionizing particle transport (Monte Carlo method) for a mathematical human phantom with arms and hands placed loosely along the sides of the body. The resulting dose conversion factors for absorbed doses in fingernails can be used to assess the dose distribution and magnitude in practical dose reconstruction problems. For purposes of estimating dose in a large population exposed to radiation in order to triage people for treatment of acute radiation syndrome, the calculated data for a range of energies having a width of from 0.05 to 3.5 MeV were used to convert absorbed doses in fingernails to corresponding doses in organs and the whole body as well as the effective dose. Doses were assessed based on assumed rates of radioactive fallout at different time periods following a nuclear explosion.

Mesenchymal stem cells from human dental pulp: isolation, characteristics, and potencies of targeted differentiation.

We studied cell cultures isolated from the pulp of third molar germ of an adult human and from the skin of a human fetus on gestation day 10. Both cultures expressed similar repertoire of surface markers typical of multipotent mesenchymal cells (CD44, CD90, and CD105). Under in vitro conditions, dental pulp cells were more susceptible to factors inducing their differentiation into adipogenic, chondrogenic, and osteogenic lineage cells.

[PUBLIC ADMINISTRATION OF PERSONNEL POLICY IN REFORMING OF UKRAINIAN HEALTH CARE SYSTEM USING THE EXAMPLE OF DERMATOVENEREOLOGICAL SERVICE].

The health care system, its modernization and optimization are among the most important functions of the modern Ukrainian state. The main goal of the reforms in the field of healthcare is to improve the health of the population, equal and fair access for all to health services of adequate quality. Important place in the health sector reform belongs to optimizing the structure and function of dermatovenereological service. The aim of this work is to address the issue of human resources management of dermatovenereological services during health sector reform in Ukraine, taking into account the real possibility of disengagement dermatovenereological providing care between providers of primary medical care level (general practitioners) and providers of secondary (specialized) and tertiary (high-specialized) medical care (dermatovenerologists and pediatrician dermatovenerologists), and coordinating interaction between these levels. During research has been found, that the major problems of human resources of dermatovenereological service are insufficient staffing and provision of health-care providers;,growth in the number of health workers of retirement age; sectoral and regional disparity of staffing; the problem of improving the skills of medical personnel; regulatory support personnel policy areas and create incentives for staff motivation; problems of rational use of human resources for health care; problems of personnel training for dermatovenereological service. Currently reforming health sector should primarily serve the needs of the population in a fairly effective medical care at all levels, to ensure that there must be sufficient qualitatively trained and motivated health workers. To achieve this goal directed overall work of the Ministry of Health of Uktaine, the National Academy of Medical Sciences of Ukraine, medical universities, regional health authorities, professional medical associations. Therefore Ukrainian dermatovenereological care, in particular fixed, needs a deep and objective medical and social audit. A necessary condition for the harmonious development of dermatovenereological service is adequate staffing to ensure it to reflect changes in the structure of the provision of the assistance at various levels, as well as their effective coordination throughout the natient's medical route.

Correcting for AFM tip induced topography convolutions in protein-DNA samples.

Atomic force microscopy (AFM) imaging offers information on many unique parameters of protein-DNA complexes. However, exact lateral dimensions of molecules or protein assemblies are convoluted with the finite size of the mechanical imaging probe, the AFM tip. An approximate knowledge of the tip dimensions allows correction for these convolutions. In the past, a variety of standards for tip size evaluation have been described, such as metal beads or nanotubes. In the context of protein-DNA samples, being able to exploit the DNA directly for such lateral image (length) corrections without the need to apply additional calibration particles is highly desirable, avoiding crowding and confusion in the images. Here, we systematically evaluate and compare simple geometrical model approaches for DNA as a lateral calibration standard in AFM imaging.

Recognition rules for binding of homeodomains to operator DNA.

The spatial arrangement of interfaces between homeodomain transcription factors and operator DNA has been considered. We analyzed the binding contacts for a representative set of 22 complexes of homeodomain transcription factors with a double-stranded operator DNA in the region of the major groove. It was shown that the recognition of DNA by the recognizing _-helix of protein is governed by two contact groups. Invariant protein-DNA group of contacts includes six contacts, formed by atomic groups of coding and non-coding DNA chains with the groups of amino acids. The recognizing _-helix forms contacts by polar groups of residues Trp2 (NE1), Asn5, and Lys9 with the canonical sequence T(1)A(2)A(3)T(4) of the coding DNA chain, and contacts by residues Lys0, Arg7 and Lys11 with the sequence A(4)X(5)X(6)X(7) of a non-coding DNA chain, where X is any nucleotide. Variable protein-DNA group of contacts comprises two groups bound with the sequence T(3)A(4)X(5)X(6) of the non- coding DNA-chain. These contacts are mainly with the bases and specify the binding pattern of individual homeodomains. The invariant contact group represents a recognition pattern for transcription factors of the homeodomain family: multiple adenine-asparagine contact and six position-specific phosphate contacts mainly with lysine or arginine. Within this group, we have found three most significant invariant contacts which allow deducing the recognition rules for homeodomains. These rules are inherent for different taxonomic groups of the homeodomain family and can distinguishing members of this family from any other family of transcription factors.

[Cloning, expression, isolation and properties of thymidine kinase herpes simplex virus, strain L2].

A thymidine kinase UL23 gene (EC 2.7.1.145) from an acyclovir-sensitive strain L2 of herpes simplex virus type 1 was cloned and expressed in E. coli. Enzyme was purified by chromatography to a homogeneous state controlled by PAG electrophoresis. The Michaelis constants for the reactions with thymidine and an acyclovir were determined. It was found that enzyme phosphorilate some modified nucleosides such as d2T, d4T, d2C, 3TC, FLT, BVDU, GCV. A comparison of the purified enzyme properties and properties ofthymidine kinase of other strains of herpes simplex virus, previously published was carried out. It is shown that enzyme is inhibited by acyclovir H-phosphonate.

[Biotechnological production of acetylated thymosin beta4].

Thymosin beta4 (43 aa) is a highly conserved acidic peptide which regulates actin polymerization in mammalian cells by sequestering globular actin. Thymosin beta4 is undergoing clinical trials as a drug for the treatment of venous stasis ulcers, corneal wounds and injuries, as well as acute myocardial infarction. Currently, thymosin beta4 is produced with solid-phase chemical synthesis. Biotechnological synthesis of this peptide presents difficulties because N-terminal amino acid residue of thymosin beta4 is acetylated. In this study we propose a method for producing the recombinant precursor of thymosin beta4 and its subsequent targeted chemical acetylation. Desacetylthymosin beta4 was synthesized as a part of a hybrid protein with thioredoxin and a specific TEV (tobacco etch virus) protease cleavage site. The following scheme was developed for the purification of desacetylthymosin beta4: (i) the biosynthesis of a soluble hybrid protein (HP) in Escherichia coli; (ii) isolation of the HP by ion exchange chromatography; (iii) cleavage of the HP with TEVprotease; (iv) purification of desacetylthymosin beta4 by ultra-filtration. N-terminal acetylation of desacetylthymosin beta4 was performed with acetic anhydride under acidic conditions (pH 3). The reaction yield was 55%. Thymosin beta4 was then purified by reverse-phase high performance liquid chromatography. The proposed synthetic approach to recombinant thymosin beta4 is suitable for scale-up and can provide for the medical use of highly purified preparation with a yield of 20 mg from 1 L of culture.

[Methods of individual retrospective physical dosimetry in the problem of estimation of consequences of accidental irradiation].

The overview of the results of development, verification and application of the methods of individual retrospective physical dosimetry among population of settlements contaminated with radionuclides, which suffered from irradiation as a result of the accident in Chernobyl NPP, and among the population located in the vicinity of the Semipalatinsk nuclear test site is presented in the paper. The estimations of sensitivity of the methods of physical retrospective dosimetry are shown. The data on individual doses among population, which was irradiated as a result of accidental irradiation are presented as well.

Dental enamel EPR dosimetry: comparative testing of the spectra processing methods for determination of radiation-induced signal amplitude.

The aim of this investigation is to find out the optimal algorithm for mathematical processing of the EPR spectra of irradiated tooth enamel for estimating the amplitude of the radiation-induced signal, which is used for determination of the absorbed dose in enamel for retrospective individual dosimetry. A recently developed analytical model, which takes into account the line shape variation of the enamel EPR spectral components registered at different microwave power, was applied to spectra processing in various operation modes to simulate spectra processing techniques differing by the number of fitted parameters. The precision of dose determination at spectra processing was assessed by the root mean square deviation between experimental and nominal doses for sets of spectra of enamel samples irradiated in different doses and measured at different microwave power. It is shown that in the case of pooled enamel samples prepared as a mixture from different teeth, the higher precision of spectra processing is obtained using a model with fixed native background signal line shape (characterized by width and asymmetry parameters). In case of individual samples prepared each from a different tooth, better results are obtained using a model with variable background signal line shape.

The neutron dose conversion coefficients calculation in human tooth enamel in an anthropomorphic phantom.

In the present study, MCNP4B simulation code is used to simulate neutron and photon transport. It gives the conversion coefficients that relate neutron fluence to the dose in tooth enamel (molars and pre-molars only) for 20 energy groups of monoenergetic neutrons with energies from 10-9 to 20 MeV for five different irradiation geometries. The data presented are intended to provide the basis for connection between EPR dose values and standard protection quantities defined in ICRP Publication 74. The results of the calculations for critical organs were found to be consistent with ICRP data, with discrepancies generally less than 10% for the fast neutrons. The absorbed dose in enamel was found to depend strongly on the incident neutron energy for neutrons over 10 keV. The dependence of the data on the irradiation geometry is also shown. Lower bound estimates of enamel radiation sensitivity to neutrons were made using obtained coefficients for the secondary photons. Depending on neutron energy, tooth enamel was shown to register 10-120% of the total neutron dose in the human body in the case of pure neutron exposure and AP irradiation geometry.

[Pharmacokinetic and dosimetric characteristics of new radiopharmaceutical based on complexes of 103Pd and albumin microspheres].

Results of the study of absorbed dose formed in organs and tissues of mice after administration of new therapeutic radiopharmaceutical on the base of 103Pd and albumin microspheres (MSA) are presented. Pharmacokinetic parameters of preparation distribution in the body of animals were experimentally determined and then absorbed doses were calculated using MCNP code for the developed mathematical model of mouse. It was shown that absorption of 103Pd-MSA in tumor, physical properties of 103Pd and daughter radionuclide 103mRh provide a targeted irradiation of tumor as compared with the adjusting tissues and critical organs. In administration to tumor muscle tissue of the leg of experimental animals after 15 days following the injection of 103Pd-MSA the accumulated absorbed dose was 15 times less than corresponding one in tumor. In a critical organ (kidneys) the accumulated absorbed dose was 20 times less than in tumor. The work performed as a stage of pre-clinical testing of the radiopharmaceutical.

Supramolecular self-assembled multilayers of terpyridine-functionalized perylene bisimide metal complexes.

A terpyridine-functionalized perylene bisimide chromophore (TPBI) has been used as a building block in the stepwise, layer-by-layer fabrication of self-assembled Fe-TPBI multilayers on gold, with the assembled supramolecular chains oriented approximately perpendicular to the gold surface. Time-resolved spectroscopy measurements seem to indicate that the energy absorbed by the multilayer is promptly dissipated to the gold surface by ultrafast processes.

[A pathologist's radiological culture].

The authors analyze 8 papers on human radiation pathology, published in the journal "Arkhiv Patologii", which assess the quality of radiological information given in them. It turns out that pathologists have accumulated important facts on some types of pathology (thyroid cancer, diseases of different organs), but their dependence on the action of radiation requires more valid evidence. The absence of radiation doses in most papers reduces the validity of the conclusions of the articles. All possible internal and external causes of the found changes, and not just ionizing radiations should be considered while interpreting results.

The Third International Intercomparison on EPR Tooth Dosimetry: part 2, final analysis.

The objective of the Third International Intercomparison on EPR Tooth Dosimetry was to evaluate laboratories performing tooth enamel dosimetry <300 mGy. Final analysis of results included a correlation analysis between features of laboratory dose reconstruction protocols and dosimetry performance. Applicability of electron paramagnetic resonance (EPR) tooth dosimetry at low dose was shown at two applied dose levels of 79 and 176 mGy. Most (9 of 12) laboratories reported the dose to be within 50 mGy of the delivered dose of 79 mGy, and 10 of 12 laboratories reported the dose to be within 100 mGy of the delivered dose of 176 mGy. At the high-dose tested (704 mGy) agreement within 25% of the delivered dose was found in 10 laboratories. Features of EPR dose reconstruction protocols that affect dosimetry performance were found to be magnetic field modulation amplitude in EPR spectrum recording, EPR signal model in spectrum deconvolution and duration of latency period for tooth enamel samples after preparation.

Childhood leukaemia in Belarus, Russia, and Ukraine following the Chernobyl power station accident: results from an international collaborative population-based case-control study.

BACKGROUND: There is little evidence regarding the risk of leukaemia in children following exposure to radionuclides from the Chernobyl Nuclear Power Plant explosion on April 26, 1986. METHODS: This population-based case-control study investigated whether acute leukaemia is increased among children who were in utero or <6 years of age at the time of the Chernobyl accident. Confirmed cases of leukaemia diagnosed from April 26, 1986 through December 31, 2000 in contaminated regions of Belarus, Russia, and Ukraine were included. Two controls were matched to each case on sex, birth year, and residence. Accumulated absorbed radiation dose to the bone marrow was estimated for each subject. RESULTS: Median estimated radiation doses of participants were <10 mGy. A significant increase in leukaemia risk with increasing radiation dose to the bone marrow was found. This association was most evident in Ukraine, apparent (but not statistically significant) in Belarus, and not found in Russia. CONCLUSION: Taken at face value, these findings suggest that prolonged exposure to very low radiation doses may increase leukaemia risk as much as or even more than acute exposure. However the large and statistically significant dose-response might be accounted for, at least in part, by an overestimate of risk in Ukraine. Therefore, we conclude this study provides no convincing evidence of an increased risk of childhood leukaemia as a result of exposure to Chernobyl radiation, since it is unclear whether the results are due to a true radiation-related excess, a sampling-derived bias in Ukraine, or some combination thereof. However, the lack of significant dose-responses in Belarus and Russia also cannot convincingly rule out the possibility of an increase in leukaemia risk at low dose levels.